Varnish - is it Stradivari's ultimate secret?
Of course it’s not that simple. A simple factory violin cannot be transformed into a Stradivarius just by coating it with top-notch varnish. On the other hand, a varnish that´s too hard will prevent any instrument from deploying its beautiful timbre potential.
In the course of the last two decades, the main constituents and composition of Classical Italian violin varnish have been well investigated and analyzed. Those classical violins were covered with a cooked combination of resin and drying oil; the recipes tracing back to the Romans were already described in Pliny the Elder’s encyclopedia 'Naturalis Historiae'.
Our oil varnish already has a golden-brown color when it has finished several hours of cooking, but a violin varnish only becomes top-notch and truly finished after being charged by pigments, thereby gaining body and richness in color.
Just as in woodcutting, we follow historical recipes when we prepare our color pigments. We start by extracting the water-soluble dyes from madder root, then cook it with rock alum and precepitate a pigment by adding potash to the solution. After washing several times and drying, this becomes an intensely coloured, insoluble and lightfast pigment.
By just slightly modifying the cooking time, the temperature and the proportions among the metal salt components, we can create an entire range of bright, luminous colors!
→ watch our video "Geigenlack aus der Kaffeemaschine" (Varnish from the coffee machine)
Right photo: The cavities in the microscope slides can hold an exactly defined amount of varnish and pigment. This provides me with a beautiful, precise way of judging and comparing pigments with one another in terms of intensity, brightness, and transparency.
This method stems from my Australian friend and colleague Hugh Withycombe. Thank you so much, Hugh, for the cutie with the cavity slides!
Twenty years ago we already started to cook our own oil varnishes. However, the necessary high boiling temperatures and the fumes that emanate from the process are too much for our Hamburg inner city workshop. So we prefer cooking our varnishes along with friends and colleagues in the countryside!
It admittedly takes quite a lot of time to cook high-quality varnish. But it is definitely worth the effort!
The result is a varnish that makes the wood “shine”. It acquires a velvety texture and a surface that takes wear with time in a very beautiful way.